Thesis (Ph.D.)--Computing, Georgia Institute of Technology, 2008. / Committee Chair: Schwan, Karsten; Committee Member: Fujimoto, Richard; Committee Member: Narasimhan, Nitya; Committee Member: Pande, Santosh; Committee Member: Riley, George.

Thesis (M.S.)--University of Florida, 2004. / Title from title page of source document. Document formatted into pages; contains 61 pages. Includes vita. Includes bibliographical references.

Thesis (Ph. D.)--Duke University, 2007.

D.Phil. / Virtualization is a new infrastructure platform whose trend is sweeping through IT like a blaze. Improving the IT industry by higher utilization from hardware, better responsiveness to changing business conditions and lower cost operations is a must have in the new generation of virtualization solutions. Virtualization is not just one more entry in the long line of “revolutionary” products that have hit the technology marketplace. Many parts of the technology ecosystem will be affected as the paradigm shifts from the old one-to-one correspondence between software and hardware to the new approach of software operating on any hardware that happens to be most suitable to use at the time. This brings along with it security concerns, which need to be addressed. Security evolving in and around the virtualized system will become more pertinent the more virtualization is employed into everyday IT technology and use. In this thesis, a security model for virtualization will be developed and presented. This model will cover the different facets needed to address virtualization security.

M.Sc. (Computer Science) / Sim swop, Phishing, Zeus and SpyEye are all terms that may be found in articles concerning online banking fraud. Home users are unsure of how the configuration of their computers affects the risk profile for conducting online banking. Software installed by a home user on their computer may be malware designed to steal banking details. Customers expect banks to provide a safe online banking system. The challenge that banks have is that they cannot control the configuration that exists on a client operating system. The V-Bank system was designed to determine whether virtualisation can be used as a means to increase the security for online banking. The V-Bank system uses a virtual machine that is run from a guest that is single purpose, read-only and fulfils the configuration requirements that the bank has for a client system. The V-Bank system also utilises public and private key encryption for identification, authentication and authorisation mechanisms in the online banking system. The architecture of the V-Bank system defines online banking as an end-to-end system. It approaches online banking as a system that consists of three major components. The three major components is a client-side component, network and server-side environment. The V-Bank system gives banks the ability to provide customers with a system that is controlled from the client, through the network to the server. The V-Bank system demonstrates that virtualisation can be used to increase the security of online banking.

This thesis investigates the development of a low cost, component based facial virtual conferencing system. The design is decomposed into an encoding phase and a decoding phase, which communicate with each other via a network connection. The encoding phase is composed of three components: model acquisition (which handles avatar generation), pose estimation and expression analysis. Audio is not considered part of the encoding and decoding process, and as such is not evaluated. The model acquisition component is implemented using a visual hull reconstruction algorithm that is able to reconstruct real-world objects using only sets of images of the object as input. The object to be reconstructed is assumed to lie in a bounding volume of voxels. The reconstruction process involves the following stages: - Space carving for basic shape extraction; - Isosurface extraction to remove voxels not part of the surface of the reconstruction; - Mesh connection to generate a closed, connected polyhedral mesh; - Texture generation. Texturing is achieved by Gouraud shading the reconstruction with a vertex colour map; - Mesh decimation to simplify the object. The original algorithm has complexity O(n), but suffers from an inability to reconstruct concave surfaces that do not form part of the visual hull of the object. A novel extension to this algorithm based on Normalised Cross Correlation (NCC) is proposed to overcome this problem. An extension to speed up traditional NCC evaluations is proposed which reduces the NCC search space from a 2D search problem down to a single evaluation. Pose estimation and expression analysis are performed by tracking six fiducial points on the face of a subject. A tracking algorithm is developed that uses Normalised Cross Correlation to facilitate robust tracking that is invariant to changing lighting conditions, rotations and scaling. Pose estimation involves the recovery of the head position and orientation through the tracking of the triangle formed by the subject's eyebrows and nose tip. A rule-based evaluation of points that are tracked around the subject's mouth forms the basis of the expression analysis. A user assisted feedback loop and caching mechanism is used to overcome tracking errors due to fast motion or occlusions. The NCC tracker is shown to achieve a tracking performance of 10 fps when tracking the six fiducial points. The decoding phase is divided into 3 tasks, namely: avatar movement, expression generation and expression management. Avatar movement is implemented using the base VR system. Expression generation is facilitated using a Vertex Interpolation Deformation method. A weighting system is proposed for expression management. Its function is to gradually transform from one expression to the next. The use of the vertex interpolation method allows real-time deformations of the avatar representation, achieving 16 fps when applied to a model consisting of 7500 vertices. An Expression Parameter Lookup Table (EPLT) facilitates an independent mapping between the two phases. It defines a list of generic expressions that are known to the system and associates an Expression ID with each one. For each generic expression, it relates the expression analysis rules for any subject with the expression generation parameters for any avatar model. The result is that facial expression replication between any subject and avatar combination can be performed by transferring only the Expression ID from the encoder application to the decoder application. The ideas developed in the thesis are demonstrated in an implementation using the CoRgi Virtual Reality system. It is shown that the virtual-conferencing application based on this design requires only a bandwidth of 2 Kbps. / Adobe Acrobat Pro 9.4.6 / Adobe Acrobat 9.46 Paper Capture Plug-in

Please read the abstract in the section 00front of this document / Dissertation (MSc (Computer Science))--University of Pretoria, 2007. / Computer Science / MSc / unrestricted

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Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Physics; and, (B.S.)--Massachusetts Institute of Technology, Dept. of Mathematics, 1979. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Includes bibliographical references. / by Lee Parks. / B.S.